The present invention relates generally to axial flow combines and, more particularly, to a multi-positionable concave extension mounted on the concave and cooperable with a threshing and separating rotor to optimally remove grain from crop material.
Concave extensions such as those found in U.S. Pat. No. 4,004,404 granted on Jan. 25, 1977, to E. W. Rowland-Hill et al and in U.S. Pat. No. 4,031,901, granted on June 28, 1977, to E. W. Rowland-Hill, which are more specifically described in U.S. Pat. No. 3,696,815, granted on Oct. 10, 1972, to E. W. Rowland-Hill et al, are utilized to supplement the threshing areas of the main concaves used in axial flow combines. Such concave extensions do not allow for different positions of the rub bars thereof for varying crop characteristics and do not move with the concave when the concave is positionally moved to a different setting relative to the threshing and separating rotor. Furthermore, it would be desirable to provide a concave extension that would mount independently of the main frame of the combine, yet permit the extension to be rigidly secured for use in a threshing mold, be variably positionable relative to the concave, but be movable with the concave and be easily removable from the combine.